Craving for drugs of abuse is an important clinical phenomenon that has proven difficult to study in the laboratory. In conjunction with a positron emission tomography study of craving for cocaine, we recorded a series of autonomic measures to better characterize the response to cocaine-relevant compared to cocaine-irrelevant stimuli. The dependent measures included heart rate, vagal tone, finger and cheek temperatures, and corrugator and zygomatic facial electromyographic activity. Heart rate is expected to reflect the motor and appetitive aspects of cocaine craving, and vagal tone will be used to distinguish this effect from stress-related sympathetic activity. Decreases in finger temperature has been one of the most reliable responses to drug- related cues in the laboratory. However, this response may characterize stress-related sympathetic activation in subjects recruited from drug treatment facilities. In the present study, the subjects did not request or receive treatment, and other physiological measures, such as vagal tone and zygomatic electromyograph, were used to rule out fear-related activation. Corrugator (frowning) and zygomatic (smiling) were used to determine the subjective valence of the "craving" response in an objective manner. These data are expected to supplement our results concerning the brain correlates of craving for cocaine.